Therin lies an unfortunate problem - there are people who will acknowledge a baby as a full fledged human entity the moment sperm makes contact, and the issue is compounded by an unclear earliest time these edits can viably be made. Some might be on board if you go early enough, but that begs the question - how early is your hypothetical early? Could this question be taken as far back as overriding sperm directives and having the sperm bring in definitive traits to do something or another, thus resulting in no actual changes to a developing baby?